Detection system

ABSTRACT

Systems and methods for creating a detector network across one or more existing communications systems. In one implementation, a system is provided. The system includes a plurality of hosts, each host hosting one or more detectors operable to detect an occurrence of an event, the hosts including functionality that is not related to the detectors and including communication functionality. The system also includes a management device for managing the detectors and one or more communications networks linking the detectors and the management device using the communication functionality of the respective host.

BACKGROUND

The present disclosure relates to detection systems.

Conventional detectors provide identification and alert functionality inresponse to one or more different source events. The sensitivity andrange of a particular detector can vary depending on the type ofdetector and the strength of the source event. For example, a radiationdetector can identify the presence of a radiological event within apredefined sensitivity range. The radiation detector uses a measurementdevice, such as a Geiger counter, to detect radioactive particles thatcome into contact with the detector. Other types of detectors includebiological detectors and chemical detectors. Biological and chemicaldetectors, for example, can sample air surrounding the detector atregular intervals for analysis (e.g., using mass spectroscopy).

Typically, conventional detectors operate as independent units, whichcan be automatic or user operated. For example, if a detector, such as aradiation detector, detects an event (e.g., a source which exceeds somepredefined threshold amount), the detector can respond by triggering analarm.

SUMMARY

Systems and methods are provided for creating a detector network acrossone or more existing communications systems. Existing infrastructure canbe utilized to provide for detectors housed within existing orconventional devices. The detectors can be linked together with acentral management device such that activity and operation of multipledetectors can be coordinated from a central location.

In general, in one aspect, a system is provided. The system includes aplurality of hosts, each host hosting one or more detectors operable todetect an occurrence of an event, the hosts including functionality thatis not related to the detectors and including communicationfunctionality. The system also includes a management device for managingthe detectors and one or more communications networks linking thedetectors and the management device using the communicationfunctionality of the respective host.

Aspects of the system can include one or more of the following features.The one or more detectors can include a radiation detector. The one ormore detectors can include a biological detector. The one or moredetectors can include a chemical detector. The one or more detectors caninclude a biometric imaging detector. The one or more detectors caninclude a meteorological detector. The device can be an ATM machine. Thedevice can be a pay telephone. The device can include video monitoringequipment. The management device can be operable to control theoperation of each individual detector. The management device can beoperable to provide instructions to a detector of the one or moredetectors in response to a received alert.

In general, in another aspect, a method is provided. An alert from afirst detector of a plurality of detectors is received. An alert from asecond detector of the plurality of detectors is received. The alerttype received from the second detector is compared with the alert typereceived from the first detector. If the alert type from the seconddetector is the same as the alert type from the first detector, thealerts are processed to determine a relationship between the alerts.

Aspects of the method can include one or more of the following features.The processing can further include determining the spatial relationshipbetween the first and second detectors. The method can further includedetermining a direction of travel for a source event generating thealerts. The method can further include determining a rate of travel forthe source event using the spatial location of the first and seconddetectors and an elapsed time between the alerts. The processing canfurther include providing instructions to the first and second detectorsto provide video data associated with the time of the alert. Theprocessing can further include providing instructions to one or moredetectors of the plurality of detectors, the instructions includingplacing the one or more detectors in a heightened state.

In general, in another aspect, a method is provided. An identifiedtarget event is received at a detector management device. Instructionsassociated with the identified target event are transmitted to one ormore host devices, where the host devices each include at least onedetector. An alert is received from a detector corresponding to theidentified target event. The received alert is processed. Processing thereceived alert can further include identifying the location of thetarget event.

Particular embodiments of the invention can be implemented to realizeone or more of the following advantages. Detectors can be housed withinexisting device infrastructure in public locations. Consequently,detectors can be positioned unobtrusively or concealed. Additionally,using existing devices as hosts for the detectors can eliminate the needto establish connectivity (e.g., electrical, communications). Thedetectors can be networked into a detection system providing flexibilityin operating the detectors from a centralized detector managementdevice. Additionally, the networked detection system provides theability to both passively track events passing by the detectors as wellas to actively seek out target events according to instructions from thedetector management device.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,aspects, and advantages of the invention will become apparent from thedescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of an exemplary detection system.

FIG. 2 shows a block diagram of an example detector.

FIG. 3 shows an example detection process.

FIG. 4 shows an example process for tracking an event.

FIG. 5 shows an example process for searching for a target event.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

FIG. 1 shows a block diagram of an exemplary detection system 100. Thedetection system 100 includes host devices 102, communications network110, and detector management device 112. The host devices 102 are linkedto the detector management device 112 using the communications network110.

The communications network 110 can include one or more differentcommunications networks allowing data to pass in one or more directionsbetween each host device 102 and the detector management device 112. Thecommunications network 110 can include wired communications networkssuch as a public switched telephone network (“PSTN”) or broadbandnetwork (e.g., Ethernet, cable). The communications network 110 can alsoinclude wireless communication networks including cellular, microwave,radio frequency, and other wireless systems. The communications network110 can be a public network, private network, or a combination of both.

The detector management device 112 provides management functions for thehost devices 102. The detector management device 112 can receive datafrom the host devices 102. For example, the detector management device112 can receive alerts from the host devices 102 if an event isdetected. The detector management device 112 can determine a response tothe received alert. Additionally, the detector management device 112 cancoordinate the operation of a detector, in response to, or independentof, a received alert. In one implementation, the detector managementdevice 112 communicates with each individual host device 102 to managethe particular operation of a detector housed within the host device102, which can vary in accordance with specific conditions.

The host devices 102 include detectors 106 and device specific equipment104. Each detector 106 provides detection of one or more types ofevents. For example, detector 106 can provide one or more of radiation,biological, or chemical detection. Additionally, or alternatively,detector 106 can monitor other environmental conditions includingmeteorological (e.g., temperature, pressure, wind), and audiovisual(e.g., surveillance systems, biometric imaging).

In one implementation, each host device 102 can be a device commonlyfound in public locations, for example, building hallways, streets, andtransportation terminals (e.g., bus, train, subway, and airport). Hostdevices 102 can provide a public structure configurable to connect withthe communications network 110. The host devices 102 can be the sametype of device or can include a variety of different device types. Inone implementation, existing devices can be retrofitted to become hostdevices including one or more detectors (e.g., using a conversion kit toinstall one or more detectors in the device).

The host devices 102 include, or can be adapted to include, componentsoperable to provide particular functionality. For example, the hostdevices 102 can include connectivity components. Connectivity componentsconnect the host devices 102 to one or more communication networks 110.The connectivity components can provide the host devices 102 with IPconnectivity (e.g., using ISDN, xDSL, Cable, T-1, 802.11 wireless,etc.). Wired connectivity can include copper wiring as well as fiberoptic cables. Connectivity components can also include wirelessconnectivity to a communication network including radio frequency (“RF”)microwave, cellular, or other wireless communications systems. The hostdevices 102 can include two or more different connectivity components toprovide multiple and redundant connectivity.

Each host device 102 can also include power components. Power componentsprovide electrical power for operating components of each host device102. Power components can include connections to external power sourcessuch as AC or DC line connections. Additionally, power can be suppliedusing internal power components, for example, from one or morebatteries, fuel cells, solar panel, or other source. Host devices 102can include more than one power component to provide a primary andredundant power supply.

Each host device 102 can include other components. For example, the hostdevices 102 can include software or hardware (e.g., an applicationspecific integrated circuit) providing logic for performing one or morefunctions. A display component can be included to provide interactionwith a user. Electrical surge protection components can be included toprovide protection from electrical surges both in-line and externallygenerated (e.g., lightning). Additionally, the host device 102 caninclude components to provide lighting for the host device 102.Furthermore, the host device 102 can be weatherized for outdoor use aswell as provide concealment for the detector 106.

In one implementation, each host device 102 includes device specificequipment 104 having one or more primary functions other than to provideenvironmental detection and/or monitoring. Device specific equipment 104can include the connectivity, power, and other components describedabove. Alternatively, one or more of the components can be provided aspart of the detector 106 and incorporated into the host device 102(e.g., by retrofitting an existing device). The host device 102 can be,for example, a pay telephone, an ATM machine, a security device, publickiosk, traffic signal, or any other device, the function of whichincorporates a connection to a communications network 110.

For example, a pay telephone includes equipment for placing a circuitswitched telephone call through a PSTN. An ATM machine includesequipment (e.g., a modem) for communicating data through the PSTNassociated with monetary transactions including, for example, accountinformation, amounts withdrawn and amounts deposited. A security device(e.g., an alarm system) communicates alarm signals through a PSTN orother communications network. For example, when the security devicedetects a breach (e.g., a broken window), a signal can be transmitted bythe security device, using the communications network, to communicate analert. The ATM and security device, for example, do not provide publiccommunications in contrast with the pay telephone functionality. Otherhost devices can also be designed for use with some form of networkconnection. For example, modern traffic lights can include datacommunication connections for providing traffic management.

In an alternative implementation, the device specific equipment 104 canfunction without any preexisting communications network connection, suchthat connection can be added to the host device 102 to provide aconnection for the data communication for the detector 106 throughcommunications network 110. For example, in one implementation, thedetector 106 can be incorporated into a vending machine to create adetection system 100 when coupled to a communications network 110.Additional equipment can be added to provide the communications network110 connection for the detector 106.

FIG. 2 shows a block diagram of an example host device 102 coupled tocommunications network 110. The host device 102 includes device specificequipment 104 and the detector 106. The device specific equipment 104controls operation of the primary functions of the host device 102separate, and independent, from the detector 106. For example, in an ATMmachine, the device specific equipment 104 can include hardware and/orsoftware providing the ATM functionality. Additionally, for deviceshaving preexisting connections to communications networks, the devicespecific equipment can include equipment for connecting with thecommunications network (e.g., telephone equipment for connecting the ATMto the PSTN).

The detector 106 includes communications equipment 204, a managementdevice 206, and a sensor 208. The communications equipment 204 allowsthe detector 106 to transmit data across the communication network 110to the detector management device 112. For example, the communicationsequipment 204 can receive data from the management device 206 andprocess the data for transmission over the communications network 110.

The communications equipment can also allow the detector 106 to receivedata from the detector management device 112 through the communicationnetwork 110. For example, the communications equipment 204 can processincoming data from the communications network 110 and route the data tothe management device 206. In one implementation, the communicationsequipment 204 includes equipment for connecting to a wired networkincluding a PSTN or a broadband data network. In another implementation,the communications equipment includes wireless equipment such as atransmitter and receiver for sending and receiving data to thecommunication network 110.

In one implementation, the communications equipment 204 includes asplitter/filter module to provide simultaneous connectivity for both thedetector 106 and any preexisting communications equipment in the devicespecific equipment 104. For example, communications equipment from thedevice specific equipment 104 (e.g., telephone equipment of a paytelephone device) can connect to the communications network 110 such asa PSTN using the splitter/filter module. The splitter/filter module canbe configured to separately maintain incoming and outgoingcommunications signals from both the device specific equipment 104 andthe communications equipment 204. Consequently, the device specificequipment 104 and the communications equipment 204 can operateindependently. Additionally, in another implementation, thesplitter/filter module can provide interference filtering for signalspassing through the splitter/filter module to or from the communicationsnetwork 110.

The management device 206 manages operation of the sensor 208 andprovides sensor data to the detector management device 112. In oneimplementation, the management device 206 processes data from the sensor208 to determine whether or not an event has occurred. In an alternativeimplementation, the management device 206 performs some initialprocessing, which is then relayed to the detector management device 112for further processing. For example, images recorded by the detector 106can be transmitted to the detector management device for biometricimaging (e.g., facial recognition processing). In one implementation,the management device 206 sends data to the detector management devicecontinuously or periodically according to a schedule regardless ofwhether an event has been detected. The management device 206 can alsoreceive instructions from the detector management device 112 through thecommunications network 110. The received instructions can includeinstructions to perform particular operations with the sensor 208 aswell as instructions for initiating an alarm or other alert operation.

The sensor 208 includes measuring or sampling equipment for monitoringand/or detecting events. The sensor 208 can be configured to monitor oneor more different environmental conditions. For example, the sensor 208can monitor air for biological and chemical contaminants, detectradioactive particles, as well as measure atmospheric or meteorologicalconditions. Additionally, the sensor 208 can be configured to provideaudio and video monitoring including biometric imaging. The range of thesensor 208 can vary depending, for example, on the type of sensor andthe location of the detector. For example, in one implementation adetector can be positioned near a roadway. The sensor 208 can beconfigured to have a range capable of detecting events among nearbypeople as well as more distant automobiles passing on the street.

In one implementation, the sensor 208 detects events by collecting airsamples. The collected air samples can then be analyzed to identify thecomposition of the air sample. In one implementation, the sensorincludes a mass spectrometer or other device for identifying particularchemical and biological agents. Other types of analysis can be performedto analyze the composition of the air samples. The air samples can becollected periodically according to a predefined schedule or,alternatively, can be continuously sampled.

In another implementation, the sensor 208 detects radioactive particles.For example, the sensor 208 can include a radiation detector such as aGeiger counter. The Geiger counter records a count of the number ofdetected radioactive particles per unit time. Count totals can be sentto the management device 206 continuously or periodically. In oneimplementation, the count totals over a particular period of time aresent to the management device 206. In another implementation, counttotals are only sent to the management device 206 if a particular countthreshold is reached (e.g., the count total exceeds the backgroundradiation level by a particular amount). In one implementation, thesensor 208, alone, or in combination with the management device 206, candetermine the type of radiation detected as well as strength of theradiation. In another implementation, information associated with theparticles detected by the sensor 208 can be used to identify the type ofmaterial releasing the radiation.

Additionally, the sensor 208 can also measure environmental conditionssuch as temperature, wind velocity, and pressure. The sensor 208 canprovide continuous readings or can take periodic samples, which aretransmitted to the management device 206. Audio and video recordingsensors can record continuously or on-demand through commands receivedfrom the management device 206. In one implementation, for biometricimaging, the sensor 208 can record video data and transmit the data tothe management device 206 for processing such as feature detection forfacial recognition. Alternatively, the recorded images gathered by thesensor 208 can be transmitted to the detector management device 112 forbiometric processing.

FIG. 3 shows an example detection process 300. A detector (e.g.,detector 106) housed within a device (e.g., host device 102) monitorswithin the range of a sensor (e.g., sensor 208) (step 302). Themonitoring of the detector can be independent of the functions of thehost device (e.g., by device specific equipment 104). For example, thedetector operation can be independent from operations of a host ATM. Thesensor range can depend on the type of sensor, the type of sensingprocess (e.g., air sampling) as well as the strength of the detectedevent source (e.g., stronger radiation sources can be detected from agreater distance). The monitoring can be continuous monitoring orperiodic monitoring according to a predefined schedule. For example, thedetector can monitor at particular times during the day (e.g., during“rush hour”) or periodically at a particular rate (e.g., once an hour).

In one implementation, the monitoring schedule can be set and adjustedby the detector management device (e.g., detector management device112). The detector can also provide on-demand monitoring according toinstructions from the management device (e.g., management device 206) orfrom the detector management device.

During the monitoring process, a determination is made as to whether anevent has occurred (step 304). For example, if a monitored environmentalcondition exceeds a predetermined threshold value an event can betriggered. If no event has occurred, the detector continues monitoring.If an event has occurred, the event is processed (step 306). The eventis processed, for example, by the management device. Processing caninclude verifying the sensor results. In one implementation, an initialreading by the sensor can require subsequent processing, for example,taking another sample from the sensor and comparing the results in orderto verify the alert.

In one implementation, a chemical or biological sensor can have a lowinitial threshold level for triggering a possible event, but furtherprocessing can be required in order to eliminate false positive results.In another implementation, for biometric imaging, an initial facialrecognition match, for example, can require additional image processingto confirm the match.

If the event processing verifies the event, an alert is generated (step308). The generated alert can then be reported to the detectormanagement device (step 310). In some implementations, an alarm isgenerated in addition to the reporting action. For example, if adetected environmental agent (e.g., radiation, chemical, biological)exceeds some predetermined maximum threshold level, an alarm canautomatically be generated. In other implementations, the detectorcontinues monitoring and waits for instructions from the detectormanagement device.

The detector can receive further instructions from the detectormanagement device (step 312). The instructions can include, for example,generating an alarm, logging the event, taking a new measurement forcomparison, or other action. Generating an alarm can include emitting anaudible siren or alert message audible within a particular range of thedevice. The instructions can also include a request for additional dataassociated with the detected event. For example, the instructions canrequest video or audio data corresponding to the time surrounding thedetected event.

In one implementation, the detector management device can be used toidentify and track detected events across a network of detectors in thedetection system. For example, the detectors can be positionedthroughout a city (e.g., within host devices) where they can passivelydetect events passing within range of the individual detectors andreport the detected events to the detector management device. FIG. 4shows an example process 400 for tracking events using a detectionsystem having a network of detectors.

The detector management device can receive an alert from a firstdetector in the network of detectors (step 402). For example the firstdetector can detect a threshold amount of radioactive particles andtransmit an alert to the detector management device. The detectormanagement device can log the alert as well as provide particularinstructions to the alerting detector. For example, the detectormanagement device can provide instructions to the detector to takeadditional readings to verify the previous alert or instructions tochange the rate of measurements (e.g., increase periodic measuringrate).

Additionally, the detector management device can instruct the alertingdetector not to produce an alarm in order to surreptitiously track theevent source. In one implementation, the detector management device canalso provide instructions to nearby detectors in the detection system,for example, to place the detectors in a heightened state for use intracking the event source. The heightened state can include increasingsensor activity (e.g., increasing the sampling/detection rate) of thedetectors, focusing the detector to a particular environmental agent(e.g., radioactive particle detection), and activating video and/oraudio monitoring equipment.

The detector management device can receive an alert from a seconddetector in the network of detectors (step 404). The detector managementdevice can compare the type of alert from the second detector with thealert from the first detector (step 406). If the type of alert from thesecond detector is different from the type of alert from the firstdetector, the alert from the second detector can be processedindependently and in a similar manner as the alert from the firstdetector.

However, if the type of alert received from the second detector is thesame as the alert received from the first detector (i.e., a radiationalert), then additional processing can be performed (step 408). In oneimplementation, the additional processing can be performed to determinethe relationship between the alerts. For example, the spatialrelationship between the first and second detectors is determined. Thus,for detectors in the network positioned in devices throughout an urbanarea, for example, the detector management device can track the motionof a substance generating the alert in the respective detectors usingthe location of the alerting detectors. Furthermore, the time intervalbetween the alerts can indicate the mode of transportation of thesubstance causing the alert. For example, a short time period relativeto the distance between the alerting detectors indicates that the eventsource is located within a vehicle. The detector management devicecontinues to monitor the network for additional events (step 410).

In one implementation, corresponding video from the detectors for a timeperiod surrounding the alert can be compared for both alerting detectorsto identify common features such as suspect individuals or vehicles.This information can be appropriately reported (e.g., provided to lawenforcement agencies). Additionally, possible locations of the substancecan be estimated by the detector management device based on thedirection of travel and rate of motion. Other detectors in the networkalong the possible travel routes can be placed on a heightened state.

In another implementation, the network of detectors can receiveinstructions from the detector management device to actively search fora particular target event. FIG. 5 shows an example process 500 foractive detection. The detector management device receives an identifiedtarget event (step 502). For example, the identified target event can besupplied by a user input. For example, the target event can be anindividual (e.g., to detect using biometric imaging) or a suspectedenvironmental agent being transported through the region covered by thedetection system.

The detector management device transmits instructions associated withthe identified target event to detectors in the network of detectors(step 504). The detector management device can transmit to all thedetectors or to a subset of the detectors in the network of detectors.The instructions can include instructions to actively search for theidentified target event. For example, the identified target event can bea biometric imaging target, such as a particular individual of interest.In another implementation, the instructions can place the detectors in aheightened state, as discussed above, focused on the identified targetevent.

The detector management device can receive one or more alerts from thedetectors indicating that the identified target event has been detected(step 506). The detector management device can identify the location ofthe identified target event using the known positions of the detectors(step 508). Additionally, the detection management device can continueto track the target event and/or notify law enforcement.

Embodiments of the invention and all of the functional operationsdescribed in this specification can be implemented in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Embodiments ofthe invention can be implemented as one or more computer programproducts, i.e., one or more modules of computer program instructionsencoded on a computer-readable medium for execution by, or to controlthe operation of, data processing apparatus. The computer-readablemedium can be a machine-readable storage device, a machine-readablestorage substrate, a memory device, a composition of matter effecting amachine-readable propagated signal, or a combination of one or morethem. The term “data processing apparatus” encompasses all apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, or multiple processors or computers.The apparatus can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them. A propagated signal is an artificially generated signal, e.g.,a machine-generated electrical, optical, or electromagnetic signal thatis generated to encode information for transmission to suitable receiverapparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a stand-alone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub-programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application-specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors and anyone or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto-optical disks, or optical disks. However, a computerneed not have such devices. Moreover, a computer can be embedded inanother device, e.g., a mobile telephone, a personal digital assistant(PDA), a mobile audio player, a Global Positioning System (GPS)receiver, to name just a few. Computer-readable media suitable forstoring computer program instructions and data include all forms ofnon-volatile memory, media and memory devices, including by way ofexample semiconductor memory devices, e.g., EPROM, EEPROM, and flashmemory devices; magnetic disks, e.g., internal hard disks or removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks. Theprocessor and the memory can be supplemented by, or incorporated in,special purpose logic circuitry.

To provide for interaction with a user, embodiments of the invention canbe implemented on a computer having a display device, e.g., a CRT(cathode ray tube) or LCD (liquid crystal display) monitor, fordisplaying information to the user and a keyboard and a pointing device,e.g., a mouse or a trackball, by which the user can provide input to thecomputer. Other kinds of devices can be used to provide for interactionwith a user as well; for example, feedback provided to the user can beany form of sensory feedback, e.g., visual feedback, auditory feedback,or tactile feedback; and input from the user can be received in anyform, including acoustic, speech, or tactile input.

Embodiments of the invention can be implemented in a computing systemthat includes a back-end component, e.g., as a data server, or thatincludes a middleware component, e.g., an application server, or thatincludes a front-end component, e.g., a client computer having agraphical user interface or a Web browser through which a user caninteract with an implementation of the invention, or any combination ofone or more such back-end, middleware, or front-end components. Thecomponents of the system can be interconnected by any form or medium ofdigital data communication, e.g., a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), e.g., the Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of the invention or of what may beclaimed, but rather as descriptions of features specific to particularembodiments of the invention. Certain features that are described inthis specification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable subcombination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understand as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

Thus, particular embodiments of the invention have been described. Otherembodiments are within the scope of the following claims. For example,the actions recited in the claims can be performed in a different orderand still achieve desirable results.

1. A method comprising: receiving a first alert from a first detector ofa plurality of detectors; receiving a second alert from a seconddetector of the plurality of detectors the second detector beingdifferent from the first detector; comparing a second alert typereceived from the second detector with a first alert type received fromthe first detector; if the second alert type from the second detector isthe same as the first alert type from the first detector, processing thealerts to determine a relationship between the alerts.
 2. The method ofclaim 1, where the processing further comprises: determining the spatialrelationship between the first and second detectors.
 3. The method ofclaim 2, further comprising: determining a direction of travel for asource event generating the alerts.
 4. The method of claim 3, furthercomprising: determining a rate of travel for the source event using thespatial location of the first and second detectors and an elapsed timebetween the alerts.
 5. The method of claim 1, where the processingfurther comprises: providing instructions to the first and seconddetectors to provide video data associated with the time of the alert.6. The method of claim 1, where the processing further comprises:providing instructions to one or more detectors of the plurality ofdetectors, the instructions including placing the one or more detectorsin a heightened state.